1. Field of the Invention
The present invention relates to animal feed compositions enhanced with certain antibiotic biomass and processes for preparing the same. More specifically, the invention relates to an animal feed admixed with an antibiotic-containing biomass derived from the fermentation of amphotericin A or B, virginiamycin, leucomycins, levorin, filimarisin, partricin or trichomycin
2. Description of the Related Art
Polyene antibiotics have been produced in purified form and are known, in this form, to be effective antibiotic agents for a number of uses in post-formed formulations such as aqueous suspensions.
Natamycin, an effective antifungal agent, has been disclosed as an animal feed supplement to enhance growth (see U.S. Pat. No. 4,536,494). In this feed supplement, dry crystalline natamycin in effective amounts is physically mixed with feed grain or the like.
U.S. Pat. No. 4,132,777 discloses aqueous suspensions of natamycin formulated as an aqueous suspension for use on animals to control diseases such as ringworm.
Similarly, U.S. Pat. No. 4,950,477 discloses aqueous aerosol suspensions of pure polyenes including pimaricin for control of various fungal diseases in humans and animals.
Canadian Patent 684,259 discloses feed additives of Candida albicans fermentation product, with or without the inclusion of an antifungal agent such as nystatin or pimaricin. This reference also discloses that chlortetracycline has been used in feed and can be admixed with Candida albicans fermentation product.
U.K. Patent Application 2,106,498 discloses the use of Streptomyces SF-1(ASA), NC1B 11738 to produce a new tetraene and also pimaricin. The activity of the fermentation broth is recorded, but no use of the fermentation biomass is disclosed.
U.S. Pat. No. 4,395,491 discloses the use in fodder of salinomycin in its biomass to promote growth of ruminants and pigs. Similar disclosures are contained in U.S. Pat. No. 4,291,053.
U.S. Pat. No. 3,802,998 relates to a process for producing levorin. The activity of levorin is measured in the fermentation broth, but no specific use is disclosed nor are there any disclosures of using this polyene as a dry biomass. Similarly, levorin and levoristatin activities are measures in the fermentation broth, as disclosed in U.K. Patent 1,254,212.